Ghrelin stimulates proliferation of human osteoblastic TE85 cells via NO/cGMP signaling pathway.
Ghrelin regulates bone formation and osteoblast proliferation, but the detailed signaling pathway for its action on osteoblasts remains unclear. In human osteoblastic TE85 cells, we observed the effects and intracellular signaling pathway of ghrelin on cell proliferation using BrdU incorporation method. Ghrelin, at 10(-10)-10(-8) M concentration, significantly increased BrdU incorporation into TE85 cells. The action of ghrelin was inhibited by D: -Lys3-GHRP-6, a selective antagonist of GHS-R. Nitric oxide (NO) scavenger hemoglobin and the NO synthase inhibitor NAME eliminated the stimulatory action of ghrelin on proliferation, while NO donor SNAP and NO synthase substrate L-AME stimulated proliferation of osteoblastic TE85 cells. The cGMP analogue, 8-Br-cGMP, stimulated TE85 cell proliferation, and ghrelin did not enhance proliferation in the presence of 8-Br-cGMP. Inhibition of cGMP production by the guanylate cyclase inhibitor prevented ghrelin-induced osteoblastic TE85 cell proliferation. In conclusion, ghrelin stimulates proliferation of human osteoblastic TE85 cells via intracellular NO/cGMP signaling pathway.
Wang
Deng-Hu
DH
Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
Hu
Yun-Sheng
YS
Du
Jun-Jie
JJ
Hu
Yun-Yu
YY
Zhong
Wei-De
WD
Qin
Wei-Jun
WJ
D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D054439:Ghrelin / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D008954:Models, Biological; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010006:Osteoblasts / Q000187:drug effects* / Q000502:physiology; D054440:Receptors, Ghrelin / Q000378:metabolism / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects
D004791:Enzyme Inhibitors; D054439:Ghrelin; D054440:Receptors, Ghrelin; C016276:8-bromocyclic GMP; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D006152:Cyclic GMP; D019331:NG-Nitroarginine Methyl Ester